A 52-year-old tourist from Spain was killed on Thursday by falling masonry in one of Florence's most famous churches, the Basilica of Santa Croce.

The church, a top tourist attraction, is where Italian luminaries Michelangelo, Galileo Galilei and Niccolo Machiavelli are buried.

The fatal accident raised questions about the state of Italy's considerable cultural heritage, which includes numerous ageing and fragile monuments.

Culture Minister Dario Franceschini, speaking from New York, said prosecutors would conduct an investigation to determine the cause and if faulty maintenance was to blame.

The victim was struck by a decorative stone fragment that fell from a height of 66 feet as he visited the church with his wife.

According to Italian media reports, the fragment was about six inches by six inches and supported a beam.

The 15th-century basilica, which has a famed neo-Gothic facade, has been undergoing a multi-year maintenance programme in collaboration with Italy's civil protection agency, the head of the organisation that manages the church, Irene Sanesi, told the Italian news agency Ansa.

"For that reason, all of the work has been done in a constant manner over the years.

"We are really astonished at what has happened, and we ask ourselves how it could happen," she said.

Authorities were checking the stability of the church, which is expected to remain closed to visitors indefinitely.

Other deadly incidents involving Italian monuments included the 1989 collapse of a 14th-century bell tower in the northern city of Pavia into a pile of brick, marble and dust that killed four people.

The cause of the accident has never been determined.

A toddler and a disabled 30-year-old were gravely injured in July when plaster fell from the ceiling of the Acireale Cathedral in Sicily during a wedding.

In October 2012, a cornice fell from the wall of the Royal Palace of Caserta, near Naples, causing part of the roof to cave in just a few feet from tourists.